The present invention relates to apparatus and methods for controlling and manipulating rolled products, and more particularly to apparatus and methods for manipulating the tail ends of rolls (or xe2x80x9clogsxe2x80x9d) of sheet product and securing the tail ends in place on the logs.
A common problem in the sheet rewinding industry arises during the final stages of the product""s preparation. Specifically, when the sheet material (such as paper product) has been wound into a log, it is routinely necessary to secure the tail end of the rolled product against unwinding. Though there exists a number of well-known ways in which the tail end may be secured or xe2x80x9csealedxe2x80x9d (e.g., by gluing, moistening, etc.), each requires some manipulation of the tail end for correct alignment in glue application, proper rewinding, etc. Preferably, the tail of a product log is laid flat and unwrinkled against the log, with the tail being secured to the log at a position a short distance from the very end of the tail. This tail sealing arrangement leaves a small length of the end of the tail unsecured to enable the end user to grasp, unseal, and unwind the rolled product. Improper tail end manipulation during the tail sealing process can lead to a number of undesirable results, including inconsistent tail end length and wrinkles in the sealed tail.
The foregoing and following discussion concerning the sheet rewinding industry is particularly relevant to paper rewinding. Accordingly, the problems and solutions described below are presented by way of illustration in the context of paper rewinding operations, such as rewinding operations on tissue paper, toilet paper, paper toweling, and the like. However, the present invention is not limited to paper rewinding or even to the paper industry. The present invention finds applicability in any or operation in which rolled material is manipulated and/or wound. As such, reference in the present application and appended claims to xe2x80x9clogsxe2x80x9d of material include rolled product made of any material, such as paper, plastic, rubber, metal, composites, fabric, and the like. Also, the rolled product referred to herein and in the appended claims as product in xe2x80x9csheetxe2x80x9d form can be of any shape and size, including material in sheet, strip, laminate, multi-ply or other form.
A number of conventional tail sealer methods and systems exist in the art. Several of these methods and systems are designed to avoid the aforementioned undesirable results of improper tail manipulation while maintaining a high rate of product output (i.e., sealed logs per minute). However, conventional tail sealers are usually quite complex, employing expensive systems and subsystems to separate and orient a measured length of the tail of each roll in a precise manner, apply adhesive to the tail or log in a precise location, and seal the tail on the log without wrinkling. Four examples of such conventional tail sealers are disclosed in U.S. Pat. No. 5,242,525 issued to Biagiotti, U.S. Pat. No. 4,475,974 issued to Perini, U.S. Pat. No. 3,393,105 issued to C. W. Teller, Jr., and U.S. Pat. No. 5,716,489 issued to Biagiotti. The teachings of the above-listed patents are incorporated herein by reference insofar as they relate to mechanisms and assemblies for manipulating tails of product rolls or logs. Due to their complexity, such conventional systems are invariably expensive and difficult to maintain. Also, an important limitation common to virtually all conventional systems is the maximum speed at which the systems can operate. In modem systems where a fraction of a second in each rewinding operation can significantly impact output and productivity, conventional tail sealing systems typically operate adequately at low speeds but display considerable inefficiencies when run to their highest speeds. The above-mentioned system complexity and bottlenecks caused thereby are often the cause of these inefficiencies. Additionally, such systems are generally less than precise and reliable in their sealing operations, particularly when run at higher speeds.
In light of the problems and limitations of the prior art described above, a need exists for a tail sealer apparatus and method which can reliably seal rolled products at a high rate, produce a consistent and controllable length of tails sealed to the logs, generate sealed tails which have few to no wrinkles, and do so by employing a simplified system design which lowers system and maintenance cost. Each embodiment of the present invention achieves one of more of these results.
The present invention is a system and method for sealing the tails of rolled products to their respective logs. To quickly accomplish this task while maintaining sufficient control of the tails during tail sealing, preferred embodiments of the present invention can include a rotary indexer assembly for controllably feeding rolled products into the tail sealer system, an upper conveyor assembly which rolls the rolled products through the tail sealer system, a lower conveyor assembly which rolls each rolled product within the tail sealer system to unroll the tail to a glue applying position and indexes the proper tail length of each rolled product, an adhesive assembly for applying adhesive to each tail and/or to each rolled product, and an ironing roller assembly which ensures contact between the tail and the rolled product for permitting the adhesive to bond the tail to the rolled product.
In accordance with a preferred method of the present invention, a product roll (or xe2x80x9clogxe2x80x9d) is indexed into the tail sealer system by the indexer assembly. After being indexed, the log is held and preferably rotated in place between the lower conveyor assembly and the upper conveyor assembly. A roll in the lower conveyor assembly is preferably provided to rotate the log in this manner as one or more air jets blow the tail against the roll. In doing so, the length of the tail is measured by at least one sensor while the roll is precisely indexed. When the desired tail length is detected, one or more sprayers spray adhesive upon the unrolled tail and/or upon the log itself. The lower conveyor assembly and the upper conveyor assembly then preferably reverse directions to wind the tail back upon the log. Preferably, the surface speeds of the lower and upper conveyor assemblies are matched during this rewinding operation to keep the roll in place between the lower and upper conveyor assemblies until the tail is fully rewound upon the log. Alternatively, the speeds can be selected to move the log to a roll surface while the tail is being rewound. By gradually being rewound on the log as the log is rotated, the tail of the log is quickly rewound and sealed without wrinkles. The sealed log is then rolled to the ironing roller assembly for sealing the tail to the log and is finally ejected from the tail sealer system. Preferably, the orientation of the sealed log (the position of the sealed tail upon the log) is known and/or controllable to eject each sealed log from the tail sealer system in a uniform orientation. The orientation of the sealed log is preferably controlled by adjusting the speed and/or the number of rotations of the roller assembly, the conveyor assembly or both assemblies.
More information and a better understanding of the present invention may be achieved by reference to the following drawings and detailed description.